JP2017074954A - Bag mouth bundling/sealing method of packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag mouth bundling/sealing method of a packaging bag in which a bag mouth of the packaging bag can be almost completely sealed without using a binding material, and can be easily opened by the finger when opening the bag mouth.SOLUTION: A bag mouth bundling/sealing method of a packaging bag according to an embodiment of the present invention is a bag mouth bundling/sealing method of a packaging bag 1 made of plastic film material which includes: a bottom 1a with a predetermined size; a side part 1b extended upward from the bottom by a predetermined length; and a bag mouth 1bhaving an opening 1c above the side part. The bag mouth bundling/sealing method of a packaging bag comprises: a twisting neck formation step in which the bag mouth 1bof the packaging bag 1 is, after squeezing/bundling it toward an approximate center of the opening 1c, twisted a predetermined times in a predetermined direction to form a twisting neck 4a with a predetermined length; and a heat welding/heat cutting step of the twisting neck in which the twisting neck 4a is heat-welded after finishing the previous step, an upper part of the twisting neck is heat-cut, and a welding and sealing part 5 is formed at the heat-cut bag mouth to seal it.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for concentrating and sealing a bag mouth of a packaging bag, and more particularly, a bag for a packaging bag in which a bag mouth of a packaging bag made of a plastic film is hermetically sealed without using a binding material such as a bag seal tape. The present invention relates to a mouth-sealing sealing method.

  Foods such as vegetables, fruits, and confectionery are generally distributed and sold in packages packed in plastic film. This packaging bag has different shapes and sizes depending on the food to be packaged, but the bag mouth is usually filled with food and then bag-sealed tape (also called bag sealer tape). It is sealed with a binding material. For example, the packaging bags described in the following Patent Documents 1 to 4 have a bag mouth sealed with a binding material such as a tape, a sealing metal fitting, or a metal clip.

JP-A 63-272637 Japanese Patent Laid-Open No. 02-085116 Japanese Patent No. 2771463 Japanese Patent Laid-Open No. 11-165713

Each of the packaging bags described in Patent Documents 1 to 4 has the following problems because the bag mouth is sealed with a binding material such as a tape, a sealing metal fitting, or a metal clip.
One problem is that various types of binding materials are required, so these binding materials must be kept in stock, and the storage management is troublesome and costly. Another problem is that the binding material attached to the bag mouth damages other commodities and becomes bulky and inferior when arranged on a display shelf.

  Another problem is that the film at the converging part is not evenly adhered (welded) simply by tightening the bag mouth with a binding material, so that sufficient pressure resistance is not obtained, and outside air enters and is packed. The quality of the goods may not be maintained. Another problem is that if the binding material is made of metal, metal powder is generated during crimping, which is not preferable as an environment for the food packaging process, and the quality control of the packaging bag performed by the metal detection method. In this case, the metal reacts with the metal detecting means, which may cause inconvenience in detecting the metal as a foreign object. Another problem is that when opening the bag mouth, it is difficult to open the bag mouth, it is troublesome to remove the binding material, and a cutting tool is required.

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide a packaging bag that can be easily opened with fingers without using a cutting tool while opening the bag mouth of the packaging bag almost completely without using a binding material. An object of the present invention is to provide a bag mouth focusing and sealing method.

  In order to achieve the above object, a bag mouth concentrating sealing method for a packaging bag according to a first aspect of the present invention includes a bottom portion having a predetermined size, a side portion extending upward from the bottom portion by a predetermined length, A bag mouth converging sealing method for a packaging bag made of a plastic film material having a bag mouth portion having an upper opening, wherein the bag mouth portion of the packaging bag is constricted toward a substantially center of the opening. A twisting neck forming step for forming a twisted neck portion of a predetermined length by twisting in a predetermined direction after a predetermined number of times; and after twisting the twisted neck portion, The upper end portion from the neck is thermally cut, a welded sealing portion is formed in the thermally cut bag mouth portion, and the torsion neck heat sealing and heat cutting step for hermetically sealing the bag mouth, It is characterized by including.

  In addition, the bag mouth converging sealing method of the packaging bag of the second aspect of the present invention is the same as the bag mouth concentrating sealing method of the packaging bag of the first aspect, in the thermal welding and thermal fusing step of the twisted neck. The welded sealed part is composed of a hard outer shell obtained by melting and hardening a film material by thermal welding, and a weak / unwelded part where the thermal welding is weak and the central part is not thermally welded from the outer shell toward the central part. It is formed.

  Further, the bag mouth converging sealing method of the packaging bag of the third aspect of the present invention is the same as in the bag mouth converging sealing method of the packaging bag of the first or second aspect, wherein the twisted neck is thermally welded and thermally fused. In the above, a groove having a predetermined depth is formed in the outer shell of the welded sealed portion.

  Further, the bag mouth concentrating sealing method of the packaging bag according to the fourth aspect of the present invention is the bag mouth concentrating sealing method of the packaging bag according to any one of the first to third aspects, wherein the packaging bag includes the side portion. In addition, a non-through hole group or slit group composed of a plurality of non-through holes or grooves is formed in a region having a predetermined width length from the bag mouth portion toward the bottom portion.

  Further, the bag mouth converging sealing method of the packaging bag of the fifth aspect of the present invention is the bag mouth concentrating sealing method of the packaging bag of the fourth aspect, wherein the slit of the slit group is made of the plastic film material. It consists of a non-penetrating recess groove that is indented by a predetermined depth from one surface to the other surface and bulges the bottom portion outward from the other surface. The recess groove is thicker from the upper opening toward the bottom. It is characterized in that the gas is made thin by gradually reducing the thickness of the bottom and forming the thinnest bottom.

  Furthermore, the bag mouth focusing sealing method of the packaging bag according to the sixth aspect of the present invention is the bag mouth focusing sealing method of the packaging bag according to any one of the first to fifth aspects, wherein the plastic film material is polypropylene ( It is a film material having a single layer or multilayer structure of any one of PP), polyethylene (PE), polyethylene terephthalate (PET), and nylon (PA).

  According to the bag mouth focusing and sealing method of the packaging bag of the first aspect of the present invention, the bag mouth portion is squeezed and focused toward the approximate center of the opening, and then twisted a predetermined number of times in a predetermined direction to obtain a predetermined length. Neck formation process for forming the neck, and after completion of this neck formation process, the neck is welded, while the upper end is thermally cut from the neck and welded to the thermally cut bag mouth. The bag neck of the packaging bag can be sealed almost completely without using a binding material by the heat-sealing and heat-cutting process of the twisted neck that forms a sealed part and seals the bag. . In addition, the hermetically sealed bag mouth can be easily opened by twisting back the hermetically welded portion in the reverse direction so that the welded portion can be easily unwound.

  According to the bag mouth converging sealing method of the packaging bag of the second aspect, the welded sealed part is formed by a heat-welded outer shell obtained by melting and hardening a film material, and the heat-sealing from the outer shell toward the center. Since the center part is formed with weak and unwelded parts that are not thermally welded, the heat-sealed bag mouth can be sealed almost completely, but when the bag mouth is opened, the welded sealed part is twisted in the opposite direction. By opening it back, it becomes easier to open the welded part, so it is easier to open.

  According to the bag mouth convergence sealing method of the packaging bag of the third aspect, since the groove of the predetermined depth is formed in the outer shell, when the bag mouth is opened, the welded sealing portion is twisted back in the reverse direction. As a result, the welded portion can be easily and easily opened, so that it is easier to open.

  According to the bag mouth concentrating sealing method of the packaging bag of the fourth aspect, the non-through hole group slit group consisting of a plurality of non-through holes or grooves is formed in the vicinity of the bag mouth portion. At the time of opening, the sealed weld neck is twisted back in the opposite direction, so that the weld location can be easily opened and the bag mouth is opened. Following this opening, the packaging bag is torn from the non-through hole group slit group Therefore, opening becomes easier.

  According to the bag mouth converging sealing method of the packaging bag of the fifth aspect, since the packaging bag has gas permeability, gas for a wide range of applications, such as MA packaging, double packaging, kimchi, pickles, etc. A wide variety of items such as unwrapped packaging and other air-permeable packaging materials for fungi and fungi can be packaged, and packaging bags filled with these items can be sealed almost completely at the mouth of the bag. Can be easily done.

  According to the bag mouth convergence sealing method of the packaging bag of the sixth aspect, the plastic film material is one of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), and nylon (PA). Since the film has a layer or multi-layer structure, these are not special materials, and can be easily obtained, and the packaging bag used for the bag mouth converging sealing method can be made inexpensive.

FIG. 1A is a front view of a packaging bag and FIG. 1B is an IB portion of FIG. 1A, illustrating a packaging bag in which a bag mouth is hermetically sealed by a bag mouth convergence sealing method according to an embodiment of the present invention. 1C is an enlarged view of one slit of FIG. 1B, and FIG. 1D is a cross-sectional view of ID-ID of FIG. 1C. 2 shows a modification of the slit group of FIG. 1A, FIG. 2A is an enlarged view of the slit group in which the IIA portion of FIG. 1A is enlarged, FIG. 2B is an enlarged view of one slit of FIG. 2A, FIG. 2D is a cross-sectional view of the slit forming process, and FIG. 2E is a cross-sectional view of IIE-IIE in FIG. 2B. It is process drawing of the bag mouth convergence sealing method of the packaging bag which concerns on embodiment of this invention. 4A is an external view of the welded sealing portion shown in FIG. 3E, FIG. 4B is a sectional view taken along IVB-IVB in FIG. 4A, and FIG. 4C is a sectional view taken along IVC-IVC in FIG. 5A and 5B are perspective views showing modifications of the welded sealing portion shown in FIG. 3E. It is the schematic of the principal part of the heat welding and heat fusing apparatus used at the twist neck heat fusing and heat fusing process illustrated in FIG. 3D. It is the perspective view which showed the bag mouth opening state of the packaging bag sealed with the bag mouth focusing sealing method of a packaging bag.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment shown below exemplifies the bag mouth converging sealing method for embodying the technical idea of the present invention, and is not intended to specify the present invention. Other embodiments within the scope of the claims are equally applicable.

  First, an example of a packaging bag in which a bag mouth is hermetically sealed by a method of converging and sealing a bag mouth according to an embodiment of the present invention will be described with reference to FIGS. 1 illustrates a packaging bag in which the bag mouth is hermetically sealed by the method of converging and sealing the bag mouth of the present invention. FIG. 1A is a front view of the packaging bag, and FIG. 1B is an IB portion of FIG. 1A. FIG. 1C is an enlarged view of one slit, FIG. 1D is a cross-sectional view of ID-ID in FIG. 1C, FIG. 2 shows a modification of the slit group in FIG. 1A, FIG. FIG. 2B is an enlarged view of one slit of FIG. 2A, FIGS. 2C and 2D are sectional views of the slit forming process, and FIG. 2E is a sectional view of IIE-IIE of FIG. 2B. FIG.

  As shown in FIG. 1A, the packaging bag 1 has a bottom portion 1a having a predetermined size, a side portion 1b extending upward from the bottom portion by a predetermined height, and an opening 1c above the side portion. It is formed of a bag made of a plastic film material in which a space 1d having a predetermined size is formed.

Further, the packaging bag 1 refers to the outer periphery predetermined length H ₁ lowered area towards the opening 1c to the bottom 1a to the side 1b and the bag mouth portion 1b _1, this portion is hermetically sealed. Further, a region where the predetermined length H _{2 is} further lowered from the bag mouth portion 1b ₁ toward the bottom portion 1a is referred to as a slit region 1b _2, and a plurality of slits 2 ₁ (3 ₁ ) (see FIG. 2A) are included in this region. Slit group 2 (2A) is formed. Of the slit group 2 (2A), as will be described later, the slit group 2 is a gas permeable portion that allows gas to permeate from one direction and prevents permeation from the opposite direction.

  The packaging bag 1 is manufactured by selecting the shape, size, film material, and the like suitable for the type, size, amount, and weight of the article to be packaged.

  The plastic film material constituting the packaging bag 1 is a single-layer or multi-layer plastic film such as polypropylene (PP), biaxially stretched polypropylene film (OPP), polyethylene (PE), polyethylene terephthalate (PET), nylon (PA), etc. It is. In addition, this film material is not limited to these, Another plastic film may be sufficient. Moreover, although the slit group 2 is formed in this film material, this slit group 2 may be provided in one layer or all the layers of a multilayer structure film. That is, after forming a slit in a single layer of film, lamination may be performed to form a multilayer structure, or a slit may be formed in a multilayer structure film.

  These processing methods are appropriately selected depending on the type or application of the resin constituting the film. As an example of the multilayer structure, for example, a film having both high gas barrier properties and sealing properties can be obtained by laminating PE having a good sealing function on PA and PET having high gas barrier properties. The thickness of the film material is not particularly limited, but is preferably in the range of 15 to 100 μm. When the thickness is less than 15 μm, it is difficult to form a slit, and for example, when used with a packaging film, sufficient strength may not be obtained. If it exceeds 100 μm, processing becomes difficult. Therefore, the thickness of the film material is appropriately selected within these ranges depending on the type of film resin, the application, and the like.

Slit group 2, in the slit region 1b 2 _(see FIG. 1A.), Aligned in a substantially straight line with a predetermined spacing a plurality of slits 2 ₁ toward the bottom 1a from the opening 1c, these alignment A plurality of slit rows are formed with a predetermined gap. That is, these slit rows are arranged substantially parallel to the side portion 1b with a predetermined gap.

Individual slits 2 _first slit group 2 has a non-through groove consisting of narrow grooves of the same shape. That is, the slits 2 _1, as shown in FIG. 1D, the thickness towards the bottom 2c from the top of the opening groove 2a through the side 2c by gradually inflated shape becomes mountain thin, the bottom other surface In addition, the bottom portion 2c is thinned most outwardly, and the cross-sectional shape is formed in a substantially U shape. Specifically, as shown in FIGS. 1C and 1D, it has a width length w, a length l, and a predetermined depth. The width length, length, and depth are not particularly limited, but the width length w is preferably 100 to 500 μm and the length l is preferably 1.2 to 2.6 mm.

The depth is about 0.7 to 2.2 times as measured from the film surface, and it is preferable that the depth d is 0.7 to 2.2 times the thickness d. Furthermore, it is preferable that the thinnest wall thickness of the bottom 2c is 2 μm to 20 μm. This wall thickness is the same for both single-layer and multi-layer films. Moreover, although the space | interval between the adjacent slits of the slit group 2 is not specifically limited, About 1.5-3.0 mm is preferable. Therefore, the slit is appropriately selected depending on the type of film resin, the application, and the like. The slit group 2 by the arrangement, each of the slits 2 ₁ gas is transmitted from one direction, and intended to be blocking transmission from opposite directions.

Slits 2 _1, although the cross-sectional shape into a substantially U-shape, not limited thereto, other shapes, for example may be the cross-sectional shape V-shaped or other shapes. In the slit group 2, a plurality of slits having a predetermined length are arranged discontinuously, but may be made continuous. In the case of continuous slits, the arrangement of continuous slits can be linear, polygonal, or curved. The amount of gas permeation of the slit and slit group can be adjusted by changing the shape and thickness of the bottom. In place of the slit, a recessed hole may be used. This recessed hole shall be a hole having a circular or elliptical opening and depth. In the case of a round hole, the diameter is, for example, 30-1500 μm, and the thickness of the thinnest part at the bottom is 2-70 μm.

Instead of the slit group 2 comprising a plurality of slits 2 _1, a plurality of non-through hole or non-through grooves having no gas permeability may be (hereinafter, referred to as non-through holes group.). According to this non-through hole group, the vicinity of the bag mouth can be easily opened by raising the fingernail.

  According to the packaging bag 1 provided with the slit group 2, since it has gas permeability that allows gas to permeate from one direction and prevents permeation from the opposite direction, it can be used in a wide range of applications such as MA packaging and double packaging. Various kinds of articles can be packaged, such as degassing packaging such as kimchi, pickles, etc., and other breathable packaging materials for fungi cultivation. In addition, this point is described in detail in Japanese Patent Application Laid-Open No. 2011-255961 in which the name of the invention relating to the application of the present applicant is “gas permeable film, manufacturing method thereof and container using the gas permeable film”. is there.

  In addition, the packaging bag filled with these articles can seal the bag mouth almost completely, but also becomes easy to open. This unsealing can be further expanded by tearing a slit group or a hole group following the unsealing, while opening by sealing back the welded sealing portion described later. It can also be opened by placing a fingernail in the slit group or the non-through hole group. In addition, since the slit groups 2 and the like are arranged substantially parallel to the side portions, the slit groups 2 and the like are not torn when the article is packaged. That is, the film material is extremely strong even if the bag mouth is twisted or pulled in the longitudinal direction from the material, so it does not break.

A modified slit group 2A will be described with reference to FIG. The slit County 2A includes a plurality of slits 3 _1, each slit 3 _1, as shown in FIG. 2E, a concave groove 3a which is recessed a predetermined depth, toward the back side at the bottom of the concave grooves 3a It is formed by a crack 3b having a predetermined depth. That is, the slit 3 ₁ includes a concave groove 3a having a predetermined depth d _2, consists of a crack 3b of predetermined length (dd _2), cracks 3b is formed in the longitudinal direction of the slit 3 _1. Symbol d indicates the thickness of the film material.

Individual slits 3 ₁ of slit groups 2A includes at least one disk-shaped rotating teeth, and a receiving roller which is provided to face at a the rotary teeth with a predetermined gap, to the outer periphery of the rotating teeth A plurality of teeth are provided at a predetermined pitch. Each tooth tip B has the same shape, and has a substantially V shape with the tip pointed at a predetermined angle Θ (see FIGS. 2C and 2D). The use of the slit forming apparatus, when the film material is passed between receiving the rotating tooth roller, a series of slits 3 ₁ is formed by these rotation. In other words, being pressed by the addendum B of the rotating teeth, a predetermined depth d ₁ pierces the tip of the film surface, a predetermined cut depth (see Fig. 2C.), The film surface is cut into V-shape Thus, the film material is elastically deformed in the direction of the arrow (see FIG. 2D). Thereafter, when the tooth tip B comes off from the film surface due to the rotation of the rotating tooth, the V-shaped dent is returned by its elastic restoring force, that is, the force in the direction opposite to the arrow. However, since the opening of the surface portion of the film surface is wide, the opening is not blocked, and becomes a concave groove 3a having a predetermined depth leaving an elongated opening. On the other hand, because the opening is small in the lower part of the inside, it is closed and becomes a crack 3b (see FIG. 2E). Since the tip of the V-shaped groove is sharp, the crack 3b is formed by returning to its original shape with a strong elastic force compared to the recessed portion in the upper part of the surface. Further, the film material has a small projection 3c protruding from this surface on the back surface thereof. The small protrusion 3c is located at a position corresponding to the lower end of the crack 3b and is formed when the film material is pressed by the tooth tip B of the rotating tooth.

As a specific example, for example, when a film material having a thickness of 40 μm is inserted to a depth of 25 μm with a rotating tooth having an angle Θ of 30 °, a slit having a depth of 14, 2 μm and the remaining crack length can be formed. The angle Θ of the rotating teeth is preferably 20 ° to 35 °, above this range, the slit 3 ₁ width dimension of the concave groove is narrow or large constituting a can not good cutting.

  According to the packaging bag 1 provided with the slit group 2A, it can be easily cut by the force of the fingertips or toes due to the concave grooves and cracks constituting the slits.

Next, with reference to FIGS. 3 to 7, the bag mouth focusing and sealing method of the present invention using the packaging bag of FIG. 1 will be described. 3 is a process diagram of the bag mouth converging sealing method of the packaging bag according to the embodiment of the present invention, FIG. 3A is an external view of the welded sealing portion of FIG. 3E, and FIG. 3B is a cross-sectional view of IIIB-IIIB of FIG. 3C is a cross-sectional view taken along line IIIC-IIIC in FIG. 3A, and FIGS. 4A and 4B are perspective views showing modifications of the welded sealed portion in FIG. 3E.
Oh, article filling process (Refer to Drawing 3A and Drawing 3B.)
First, the opening 1c of the packaging bag 1 is widened, and a predetermined amount of articles g are filled into the internal space 1d. The article may be anything such as vegetables, fruits, processed meats, confectionary foods, or other articles such as fish and shellfish. Further, when fresh vegetables, fruits, etc. are packaged in this packaging bag, the slit group 2 is provided in the packaging bag, so that the freshness can be maintained for a longer time due to the gas permeability of the slit group.

B Twist neck formation process (see FIG. 3C)
Next, the packaging bag 1 squeezes and converges the bag mouth portion 1b ₁ toward the center of the opening 1c, and the gathered bag mouth portion is in a predetermined direction, for example, clockwise (see symbol R in FIG. 4C). Are twisted a plurality of times to form a twisted neck 4a having a predetermined length (see FIG. 3C).

  The number of twists and the length of the twisted neck 4a are determined by the packaging bag to be used. That is, for the packaging bag, a packaging bag suitable for the type, size, quantity, and weight of the article to be packed inside is prepared, and the number of twists and the length of the twisted neck portion 4a according to the produced packaging bag. To decide. The number of twists of the neck is preferably at least 1 to 2 or more because a desired seal cannot be achieved if the number is small. The length of the twisted neck is short in the case of a small packaging bag that wraps a small and lightweight article, for example, around 5 to 10 mm, or in the case of a large packaging bag that wraps a large quantity and a heavy article. Is longer, for example, 1.0 to 2.0 cm. By adjusting the length of the twisted neck, as will be described later, the bag mouth can be securely sealed while being easily opened.

The twisted neck 4a is formed by a twisting operation with fingers or a dedicated twisting machine. Although not shown in the figure, this twisting machine device includes a suspending means for suspending a packaging bag 1 filled with articles, a means for twisting a portion below the bag mouth portion 1b ₁ of the suspended packaging bag in a predetermined direction, and the like. It is provided. Such a mechanical device can be easily produced by being connected to a packaging machine. According to such a twisting machine apparatus, the formation of the neck is automated and the working efficiency is improved.

By this twisting neck portion forming step, the bag mouth portion 1b ₁ is divided into a twisting neck portion 4a and an upper end portion 4b above it as shown in FIGS. 3C and 3D.

C. Heat welding and fusing process of twisted neck (see FIGS. 3D and 3E)
In this step, the twisted neck 4a is fixed by thermal welding, and the upper end 4b above the twisted neck 4a is cut by thermal fusing (melting along line aa in FIG. 3D). A welded and sealed portion 5 is formed in the cut bag mouth portion 1b ₁ , and the bag mouth (the location where the bag mouth portion is melted) is hermetically sealed by the welded and sealed portion 5. That is, while firmly fixing the twist of the neck by heat welding of the twisted neck 4a, the upper end 4b above the twisted neck 4a is cut by thermal fusing, A mountain-shaped welded and sealed portion 5 is formed in the bag mouth portion 1b _{1 so} as to protrude upward in a relatively small hill shape (see FIG. 3E), and the bag mouth is hermetically sealed almost completely. In addition, the size of the welded sealed portion 5, that is, the height, the diameter reaching the root portion, and the apex, and the like vary depending on the packaging bag used.

Furthermore, this welding sealing part 5 is explained in full detail. As shown in FIG. 4B, the welded sealing portion 5 has an outer peripheral inclined surface that gradually rises from the region where the slit group 2 is provided upward at a predetermined angle, and the top of the top that rises above the inclined surface. part 5 ₂ forms a low mound shape raised mound consisting envelope over the mountain, that is, the outer surface and the portion of the predetermined depth from the outer surface of the outer peripheral inclined surface and the top portion, a so-called outer skin layer, the film material is melted by heat welding, hardened outer skin shell 5 ₁ became hard and a weak degree of thermal welding toward the center from the outer skin shell 5 _1, heat welding is led to the center portion weak-unwelded part ₃ which is not, in are formed.

Skin shell 5 ₁ is formed in the outer skin layer having a predetermined thickness, also with one performs a function of torsional neck firmly fixed so as not returning, almost completely closed sealing the bag mouth blow the bag mouth portion It has a function to do. The outer skin shell 5 ₁ thickness (outer skin layer.) Varies depending packaging bag to be used. In other words, since the packaging bag is used that matches the type, size, quantity, and weight of the goods to be packed, the thickness is adjusted accordingly. Since opening becomes difficult, considering these balances, about 1.0 to 3 mm is preferable. Further, the weak-unwelded part ₃ of the internal, since become weak welding or unwelded state, it is possible to return easily twisting of the neck when opening the bag mouth.

Partially modified the weld sealing unit 5, there outer surface of the outer cover shell 5 _1, welded closure 5A (see FIG. 5A containing the substantially vertical plural grooves 5a from the top portion toward the root portion. Alternatively, a welded sealed portion 5B (see FIG. 5B) in which a plurality of grooves 5b are inserted in the twisting direction may be used. The formation of these grooves makes opening easier without compromising complete sealing.

  With reference to FIG. 6, a thermal welding / thermal fusing device for thermally fusing and twisting the twisted neck will be described. FIG. 6 is a schematic view of a main part of the thermal welding / thermal cutting apparatus.

The thermal welding / thermal fusing device 6 includes a neck welding portion 7 for heat welding the twisted neck portion 4a and a cutting portion 8 positioned above the device and thermally fusing the upper end portion 4b of the twisted neck portion 4a. And.頸溶attaching portion 7 is provided with a neck contact member 7a provided with a longitudinal concave groove ₇₁ of substantially semicircular, the longitudinal recessed groove ₇₁ of substantially semicircular push the twist neck longitudinal recessed groove 7 ₂ The pusher 7b is provided with a heating means, and the twisted neck 4a is heat-welded.

In addition, this neck welding part 7 uses what changed the length of the neck contact tool 7a and the pushing tool 7b according to the length of the twisted neck, and each groove | channel 5a, 5b is a longitudinally concave shape. by providing a Netsuha the groove 7 in _one form.
Further, the cutting portion 8 includes two converging cutting plates 8a and 8b provided with notch grooves 8 ₁ and 8 ₂ and facing each other with a predetermined gap, and a converging cutting plate 8c entering the gap. The two converging cutting plates 8a to 8c are respectively connected to a heat source, and the upper end of the twisted neck portion is sandwiched between the notch grooves, and the neck is tightened and thermally fused. This thermal welding / thermal fusing device 6 is an example of a device that thermally welds and twists the twisted neck, and other similar devices can be used.

  According to the bag mouth sealing method of the embodiment of the present invention described above, the packaging bag 1 can be sealed almost completely by the welded sealing portion 5 without using a binding material or the like. On the other hand, opening of the welded sealed portion is facilitated. That is, the bag mouth is almost completely sealed by determining the number of twists of the neck, the length, the length of the twisted neck, the size of the welded seal and the thickness of the outer shell, etc., depending on the packaging bag used. Can be sealed. The packaging bag to be used is determined by the type, size, quantity and weight of the goods to be packaged. The almost perfect hermetic sealing of the bag mouth can maintain the high quality of the packaged goods. In particular, if you set up a slit group and wrap fresh vegetables, fruits, etc. in a packaging bag, you can keep the freshness long. This packaging bag can be used for many purposes as described later.

At the time of opening, it can be easily opened by twisting back the welded sealing part 5. That is, by picking the welded sealing part 5 with the fingers of the dominant hand and twisting it back so as to loosen the screw, this twisting back causes the welding sealed part 5 to move counterclockwise L (the twisting direction R of the neck). backward, see Figure 3C.) return, firstly, the interior of the weak-unwelded part 5 ₃ melts, the return force is applied to the outer skin shell 5 _1, the outer skin layer is destroyed when a strong return force is applied to the skin shell By tearing and pulling the bag mouth with other fingers, the bag mouth can be greatly opened (see FIG. 7).

  Further, since the packaging bag 1 is provided with the slit groups 2 and 2A and the non-through hole group, the welded sealed portion 5 is pulled down from these portions (slit groups 2 and 2A, etc.). For the first time, the side 1b of the bag is greatly broken. This makes it very easy to remove the article. The opening can also be performed by raising a fingernail in the slit group 2, 2A and the non-through hole group. Further, since the gas-permeable slit group 2 is provided in the packaging bag 1, it can be used in a wide range of applications, for example, MA packaging, double packaging, kimchi, pickling and other degassing packages, and others such as fungi. A wide variety of articles such as cultivated breathable packaging can be packaged, and a packaging bag filled with these articles can seal the bag mouth almost completely, but can be opened easily.

DESCRIPTION OF SYMBOLS 1 Packaging bag 1b ₁ Bag mouth part 1a Bottom part 1b Side part 1c Opening 1d Space 2 (2A) Slit group 2 ₁ . 3 ₁ slit 2a opening groove 2c (slit) bottom 3a recessed groove 3b crack 4a twisted neck 4b upper end 5 welded seal 5 ₁ outer shell 5 ₂ top 5 ₃ weak / unwelded 6 heat welding / thermal fusing apparatus

Claims (6)

A bag mouth concentrating sealing method for a packaging bag made of a plastic film material having a bottom portion of a predetermined size, a side portion extending a predetermined length upward from the bottom portion, and a bag mouth portion having an opening above the side portion. And
A twisted neck forming step of forming a twisted neck portion of a predetermined length by twisting the bag mouth portion of the packaging bag toward the approximate center of the opening and then twisting it in a predetermined direction a predetermined number of times;
After the process is completed, the twisted neck is thermally welded, while the upper end from the twisted neck is thermally fused to form a welded sealed portion at the thermally sealed bag mouth. , Heat welding and fusing process of twisted neck to seal the bag mouth,
The bag mouth focusing sealing method of the packaging bag characterized by including this. In the heat welding and fusing process of the twisted neck,
The welded sealed part is formed by a hard outer shell obtained by melting and hardening a film material by thermal welding, and a weak / unwelded part where the thermal welding is weak and the central part is not thermally welded from the outer shell toward the central part. The bag mouth focusing sealing method of the packaging bag of Claim 1 characterized by the above-mentioned. In the heat welding / melting process of the twisted neck,
The method of claim 1 or 2, wherein a groove having a predetermined depth is formed in the outer shell of the welded sealing portion.   The packaging bag is formed by forming a non-through hole group or a slit group of a plurality of non-through holes or grooves in a region having a predetermined width and length from the bag mouth part to the bottom part on the side part. The bag mouth convergence sealing method of the packaging bag according to any one of claims 1 to 3.   The slit of the slit group is formed of an unpenetrated recess groove in which a bottom portion is inflated by indenting a predetermined depth from one surface of the plastic film material to the other surface, and the bottom portion bulges outward from the other surface. The bag mouth of a packaging bag according to claim 4, wherein the thickness is gradually reduced from the upper opening toward the bottom, and the bottom is formed to be the thinnest so as to have gas permeability. Focused sealing method.   The bag mouth of the packaging bag according to any one of claims 1 to 5, wherein the plastic film material is a single-layer or multilayer film material of any one of PP, PE, PET, and PA. Focused sealing method.